By Chang Jae-soon SEOUL, April 14 (Yonhap) -- South Korea expects to fully retrieve a sunken naval ship as early as this week if weather conditions permit, a key step in determining the cause of the mysterious sinking, the defense ministry said Wednesday.

Salvage operations were suspended due to high waves after the stern of the broken ship was moved to shallower waters a day earlier to make it easier to hoist up the wreckage, in which the bodies of 44 missing sailors are believed to be trapped.

But divers still hoped to tie a third chain around the ship on Wednesday, the final step before raising it out of the sea with a crane. If that operation is successful, it may be possible to pull the stern out of water on Thursday, the ministry said.

"We weren't able to resume operations this morning" because of strong winds and high waves, an official at the Joint Chiefs of Staff said.

The 1,200-ton corvette Cheonan sank on March 26 near the Yellow Sea border with North Korea. Two of the 104 crew members were found dead while 44 still remain missing and 58 others were rescued.

Survivors say a powerful explosion rocked the vessel and broke it in half, with the rear of the vessel disappearing out of sight less than a minute later. Experts have also suggested an internal explosion, "metal fatigue" in the ship and a collision with a reef.

North Korea's involvement has been suspected from the beginning as the site of the sinking lies near where the two Koreas fought bloody gun battles in 1999, 2002 and most recently in November last year. But no concrete proof has been found yet to back the suspicion.

North Korea's state media outlets have remained silent on the incident.

South and North Korea remain technically at war after the 1950-53 Korean War ended in a truce, not a peace treaty.